A new cubichnium ichnogenus and ichnospecies, Pygocephalichnium reidi, from the Pennsylvanian UNESCO World Heritage Site at Joggins Fossil Cliffs, Canada, and associated ichnotaxa
Bibliographic record
Abstract
The Carboniferous Joggins Fossil Cliffs UNESCO World Heritage Site in Nova Scotia, Canada, has long been known for its extensive paleobiodiversity. The ichnofossil record at Joggins is less known than the body fossil record. Amongst the extensive ichnological collections of the late citizen-scientist Donald Reid is a morphologically unique shrimp-shaped cubichnium (resting trace). The trace fossil is associated with a faint invertebrate trackway that leads up to the resting trace and establishes its identification as an invertebrate resting trace. The trace fossil was recovered from the upper Joggins Formation (876 m above the base), and was found in finegrained, rippled sandstones interpreted to be from an open-water to poorly drained lithofacies assemblage transition. The trace fossil slab studied here also has examples of the invertebrate resting traces Selenichnites and Rusophycus preserved in convex hyporelief; these traces are commonly attributed to horseshoe crabs and crustaceans, respectively. They co-occur in the same stratigraphic horizon with Kouphichnium trackways, interpreted to be produced by xiphosurans. The upper Joggins Formation has previously yielded body fossils of Pygocephalus shrimp preserved in organic-rich limestones and sideritic-ironstone nodules. Pygocephalus body fossils are common at Joggins, but no trace fossils have been assigned to this invertebrate, perhaps having gone unrecognized until now. The trace fossil newly described here as Pygocephalichnium reidi is interpreted to have been produced by a Pygocephalus shrimp based on its morphological similarities to known body fossils from the Joggins Formation, and we propose that this new trace fossil morphology warrants a new ichnotaxon, Pygocephalichnium reidi.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".